Generally, in the manufacturing processes for integrated circuits, semiconductor devices, and photoelectric devices, a titanium dioxide film has been extensively used. Titanium dioxide can be applied in a memory with a high capacity (such as dynamic random access memory (DRAM)) because of its higher dielectric constant, or can be applied in photoelectric devices (for example, waveguide, filter, antireflective coating, etc.) due to its high refractive index.
The most commonly used method for forming a titanium dioxide includes: (1) reactive sputtering; (2) sol-gel growing method which is performed at 800.degree. C.; (3) plasma enhanced chemical vapor deposition which is executed at less than 400.degree. C. However, high radiation generated in the sputtering process will damage the device. Moreover, high temperature required for the reactive sputtering process or sol-gel growing method also causes a damage to the fabricated device. If titanium dioxide can be grown at a lower temperature, the damage resulting from radiation and high temperature can be avoided.
Liquid phase deposition (LPD) is a method of forming a film at about room temperature so that this method has a great developing potential in the processes for manufacturing integrated circuits, semiconductor devices, and photoelectric devices.
In the previous studies about forming titanium dioxide film by liquid phase deposition, not only is the coverage of the formed titanium dioxide film not so good, but a few changes of the operating parameters will significantly influence the growth quality because of too slow deposition rate (less than 6 .ANG./min) and unstable growth. Therefore, the titanium dioxide film formed by the prior technique can not be applied in the production line due to low throughput and unstable quality.
Our previous U.S. patent application Ser. No. 09/306,080 discloses a method to solve the above-described problems. This method is characterized by that nitric acid is added to the raw material H.sub.2 TiF.sub.6 for increasing the growth rate of the titanium dioxide layer and enhancing its stability. However, the current leakage of the formed titanium dioxide layer is still not low enough and there still exists some space to improve its quality.